The chapter presents potential safety problems in hydrogen refueling stations, which are mainly caused by uncontrolled hydrogen leakages, as well as how these hazards can be analyzed. Firstly, the severity of the leakage is determined. Basing on the mass and the pressure of the leaking hydrogen, one may evaluate the range of the cloud formed by the leakage. This cloud is the space for a potential fire or explosion. Then, the size of a fire or an explosion is evaluated for chosen locations of the source of ignition. This analysis allows to understand the severity of hazardous events.